Reciving a friend request on Facebook from a complete stranger.
Usually these come from 3rd world countries or are social losers from your local community, trying to gain respect through their number of Facebook friends.
They might also be Sales Representatives, trying to reach you privately and make an emotional connection.
Facebook Friend Requests (1)
#1: "Dude, who is that kid?"
#2: "Oh, that's the loser from school. Looks like you got a fan request eh?"